Railway-traffic-controlling apparatus



"1624248 Aim! 2 1.. HOWARD RAILWAY-TRAFFIC CONTROLLING APPARATUS Filed June 21, 1926 C I INVENTOR-I Patented Apr. 12, 1927.

UN-lTED STATES PATENT OF FlQ-E.

LEMUELFpHOW'ARD, OF *EDGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, .A COR- PORATION OF PENNSYLVANIA.

RAILWAY-TRAFFIC-CONTROLLING APPARATUS.

Application filed. June 21, 1926. Serial No. 117,324.

My invention relates to railway traiiic controlling apparatus, and particularly to apparatus of the type wherein the current supplied to a track circuit and used to energrize a track relay, is periodically interrupted for the purpose of controlling train carried mechanism. One object of my invention-is the provision of means for energizing the track relayafter a train passes out of the track circuit in spite of such periodic interruptionof the track circuit current.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form of apparatus embodying my invention.

Referring to the drawing, the reference characters 1 and 1 designate the track rails of a railway, which rails are dividedby insulated joints 2 to form track sections, only one of which sections is shown in the drawing. This section is provided with a track relay R and a source of track circuit current '1. As here shown, the source of track circuit current is a. transformer, the primary 3 of which is constantly energized from a source of alternating current, not shown in the drawing, and the secondary A of which is connected across the track rails 1 and l Interposed between the secondary 4 and the rail 1 is a contact 13, which is periodically opened to interrupt the supply of current from the transformer T to the track rails. As here shown, this contact 18 is a back contact of a coding relay C which may be controlled in any suitable manner, such, for example, as by a circuit from a battery 11, through back cont-act 10 of track relay R, winding of relay C, and back contact 12 of relay G to battery 11. hen back contact 10 is closed, relay C will be alternately energized and tie-energized, so that contact 13 will be alternately opened and closed to periodically interrupt the supply of current from the transformer T to the track rails 1 and 1 Relay C will ordinarily be also controlled by traffic conditions in advance of the section illustrated in the drawing, but this control forms no part of my present invention, and is therefore omitted from the drawing to simplify the disclosure.

lit the track relay R were energized rli rectly from the track rails, as is usual in automatic signaling practice, this relay would be de-energized when the section is occupied by a train, and would remain deenergized after the train'leaves the track section if the intervals during which the track circuit current is supplied to the rails are too short to effectively energize the relay. To overcome this difficulty, I interpose between the track rails and'the track relay an energy integrating means for causing the relay to become energized by the periodically interrupted current which is supplied to the track rails when relay C is in operation. As here shown, the primary 5 of a transformer A is connected across the rails at the relay end of the section, and the secondary 6 of this transformer is connected with a heating element 7 of a thermo-sensitive relay B. This thermo-sensitive relay B also includes a thermosensitive substance 8 subjected to the heat from the heating element 7 and the substance 8 is included in a local circuit for relay R, which circuit is from a battery 9, through the substance 8 and the relay R to the battery 9. One purpose of transformer A is to prevent foreign direct current from reaching the heating element 7.

Under normal conditions, that is, when the track section is unoccupied, relay R is energized, because the heat supplied to substance 8 by the heating element 7 reduces the resistance of this substance to such value that sufficient current flows through relay R- from battery 9 to energize the relay. Contact 10 is therefore ope-n so that relay'C is de-energized and the supply of track circuit current from transformer T to the track rails is uninterrupted. \Vhen a'train enters the track section, it shunts the track circuit current from transformer A; so that the thermo-sensitive substance 8 becomes cool and therefore increases the resistance of the local circuit for relay R to such a value that this relay becomes tie-energized. The closing of back contact 10 starts the operation of relay C, so that the supply of current to the track rails from transformer T is periodically interrupted by the peri odic openingof contact 13. When the train passes out of the track section. the. heating element 7 is periodically supplied with current and therefore gradually increases the temperature of the thermo-sensitive substance 8 until this temperature reaches such a value that relay R becomes energized to open its back contact 10. This stops the operation of relay G, whereupon the supply of track circuit current again becomes uninterrupted and the apparatus is restored to its normal condition. 7

Although as here shown the relay C is controlled by a back contact of track relay R, this particular means for controlling relay G is not essential to my invention, but is desirable in order to prevent unnecessary operation of relay G while there is no train inthe section with which this relay associated.

Although I have herein shown and described only one "form of iipi'itll'tlilllS cml'iodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention what I claim is:

1. Railway trallic controlling apparatus comprising a track circuit including track rails and a source of current, a track relay, means for periodically interrupting the supply of current from said source to the track rails, and energy integrating means interposed between the rails and said relay for causing the relay to become energized by the periodically interrupted current.

2. Railway traffic controlling apparatus comprising a track circuit including track rails and a source of current, a track relay, means for periodically interrupting the sup ply of current from said source to the track rails, and a thermo-sensitive integrating device interposed between the rails and said relay for causing the relay to become encrgized by the periodically interrupted current.

3. Railway tralficcontrolling apparatus comprising a track circuit including track rails and a source of current, a track relay, means for periodically interru 'iting the supply of current from said source to the i1" rails, a heating element receiving enei from the track rails, a thermo-sensitive element subjected to the heat from said heating element, and a circuit for said relay in cluding said heating element and source of current.

4. Railway tratHc controlling apparatus comprising a track circuit including tract: rails and a source of current, a track relay, means for periodically interrupting the supply of current from said source to the track rails, a heating element receiving enern' from the track rails, a thermo-sensitive element subjected to the heat from said heating element, and means for energizing said relay when the temperature of said thermosensitive element reaches a given value.

5. Railway trailic controlling apparatus comprising a track circuit including track rails and a source of current, a track relay, means for periodically interrupting the supply of current from said source to the track rails when said track relay is open but not when it is closed, and energy integrating means interposed between the rails and said relay for causing the relay to become encrg 'ized by the periodic-ally interrupted. current.

6. Railway ti-attic controlling apparatus comprising a track circuit including track rails and a source of current, a track relay, means for periodically .interrupting; the supply of current from said source to the track rails when said track relay is open but not when it is closed, a heating element receiving energy from the track rails, a thermosensitive element subjected to the heat from said heating element, and a circuit for said relay including said heating element and a source of current. V

7. Railway tratiic controlling apparatus comprising a track circuit including track rails and a source of. current, a track relay, means for periodically interrupting the supply of current from said source to the track rails when said track relay is open but not when it is closed, and a thermo-sensitive integrating device interposed between the rails and said relay for causing the relay to become energized by the periodically in terrupted current.

8. Railway trafiic controlling apparatus comprising a track circuit including track rails and a source of current, a track relay, means "For periodically interrupting the supply of current from said source to the track rails, a transtoriucr having its primary connected with said track ,rails, a heating cle inent connected with the secondary otsaid transformer, a thermo-sensitive substance subjected to the heat from said heating element, and a circuit for said relay controlled by said substance and including a source of current.

9. Railway traflic controlliug; apparatus comprising a track circuit including track rails and a source of current, a track relay, means for periodically interrupt-ins tl-e su ply of current from said source to the true i rails. a circuit for said relay including a second source oi current, and energy integ'rat-ing means controlled by said track circuit and in turn controlling said relay circuit.

In testimony whereof I attix my signature.

LEMUEL F. HGWVARD. 

